MG42 Rail Rivets

I spent the better part of this evening trying to rivet the rails on the HF press. Very difficult work and very frustrating. These rivets kicked my butt today.

What have you found to be the best rivet method? Seems the rails are twisting a bit when I rivet them on the HF press... my method so far has been:

Use a McMaster-Carr 5/32" x 3/8" rivet and file or lathe a flat head onto it.

Use a 3/8" grade-8 bolt and coupling nut (from HD) to buck the head inside.

Press the rivet on the exposed side on the HF 12-ton press.

This takes a ton of wiggling/resetting/re-wiggling to get the rivet straight. The end result is that when I look down the rail from the rear, I swear the rail seems "twisted" such that the top is further away from the receiver than the bottom, and it is sloped downward some. Hand-fitting the reciprocator fails. I think the rail is sloped downward enough that the reciprocator now won't fit...

It seems that there is either not enough flat on the inside of the receiver (should I hammer it flat first?), or the pressure of the press is distorting the final position of the rivets.

The 1-Pat GB rivets I have are softer than the McMaster rivets, and thus require less pressure to press. GREAT for trigger guards... I think this may be what I use for my 2nd attempt. Haven't even bothered with the RH rail yet...

Are there tricks like the drill bit with AK rails? Would it make sense if I were to brace it with a drill bit on the bottom to keep the spacing for the recuperator?

I put the bucking bar similar to the one you described inside with a round pocket cut in each end and I put both rails in with a rivet on each end of the bolt/bucking bar , round heads inside rec, and then use the air chisel with riveting tool in place to peen the heads of the rivets. I found that the hammer or press method tends to distort the rec but the air chisel in short burst doesnt seem to hurt anything and you can kinda "steer" the head of the rivet as its being formed

At the risk of stating the obvious, you got a lot of things subject to movement. A couple of random thought are that you probably should cup the bolt head such that the rivet head sits in the cup. Probably will help to bolt the remaining rail rivet holes in place and replace bolt/nut with rivet as you proceed down the rail. Does Plinkers 1919a4 riveting jig open wide enough to get it around the MG-42 receiver?

At the risk of stating the obvious, you got a lot of things subject to movement. A couple of random thought are that you probably should cup the bolt head such that the rivet head sits in the cup. Probably will help to bolt the remaining rail rivet holes in place and replace bolt/nut with rivet as you proceed down the rail. Does Plinkers 1919a4 riveting jig open wide enough to get it around the MG-42 receiver?

Have you checked on MG42 site to get tips ??

good points, i have a dimple in the end of my bucking bolt that I machined by putting a 1/4" ball end mill in the tail stock of the lathe, I also have at least 3qty 8x32 screws with nuts holding the rails in place

the best way to do it is either with an air hammer or ball the heads with a tig. you need to put screws in all the holes to keep the rails aligned during the process. when you do the left rail you need to have the recuperator in place to make sure it will fit after the rail is installed.

Thanks for the feedback guys. In hindsight I think I must have cranked down too hard on the press. I'm going to cut out all the rivets and hammer it flat if need be and start over again. We have a few days of cool weather coming in so I may put off more boat work until the weekend.

Cheezy don't worry about the questions - that's what we're here for! The best thing about Gunco is that you won't get 50 "use the search tool ya noob" replies! That is in fact what motivated me to start building my website... then along comes Gunco and most everyone (myself included) has that "I'm here to help" attitude.

Believe me - if you don't have a receiver shell yet, GET ONE. Pay whatever you need to pay for it, but get it. They are becoming more scarce every day and unless someone makes US-built replacement parts, they will simply get more scarce. Barrels are second on that SHORT list. The Yugo M53 kit has everything you need, so if you get the receiver shell and the M53 kit, you should be all set. Then the fun begins!